The present study reports the use of Catla catla fish scales for the biosorption of Cr (VI) at the best operating conditions. The influence of various physico-chemical parameters like solution pH, agitation, Cr(VI) concentration, biomass dosage, contact time, biomass particle size and temperature were studied. The optimum pH for biosorption of Cr(VI) was found to be 1.0. More than 60% of the ions were removed within 60 min of contact and maximum removal was obtained after 4 hour. The adsorption capacity increased with increase in temperature and agitation speed. Freundlich and Langmuir...